How many gallons of water does this aquarium hold?
by Aquaboy on Sunday, March 7th, 2010 | 9 Comments
It’s about 3 feet X 1.5 feet X 1 foot. I got it at an auction and need to know so I can start buying stuff for it (stand, filters, etc…). Thanks 
Sounds like a 29 gallon to me, I’m almost certain of it!
Go to a store that caries aquariums and look for one that is close to your measurements and see how many gallons it holds.
It is 4.5 cubic feet and 1 cubic foot is 7.48 US gallons (liquid). So, the tank can hold 33 gallons of water, but you may need to leave some space at the top.
It could be either a 29 or a 30 gallon. The first measurement (length) will make a great deal of difference. A 29 is only 30 inches in length (30 x 12 x 18), whereas a 30 gallon is 36 inches (36 x 13 x 16).
You can also use this website to plug in the exact measurments to figure out the volume: http://www.aquaticcommunity.com/converter/volume-calculator.php
NOTE: While the actual volume may not total 29 or 30 gallons exactly, these are the volumes by which the tanks are sold. It also matters volumewise if you measure the outside of the tank or the inside, because the thickness of the glass “inflates” the actual volume.
Volume 127 l./28 gal. (33.55 US gal.)
Probable volume 114 l./25 gal. (30 US gal.)
I used a volume calculator on this site. Ha!
US gallons:33.7 gallons
UK gallons:28 gallons
CC
36″ X 18″ X 12″ X 0.00433 =33.67008gal.
Call it a 33gal.
3′ x 1.5′ x 1′ = 4.5 cubic feet
4.5cu.ft x 7.48(gal./cubic foot) = approx. 34 gallon. tank
Use this formula:
Length x Width x Height (all dimensions in inches) divided by 231 = gallons
Convert feet to inches using this equivalent 1ft=12 inches
3 feet x 12 = 36 inches length
1.5 feet x 12 = 18 inches height
1 foot x 12 = 12 inches width
Substitute: L x W x H
36 x 12 x 18 = 7776
7776 divided by 231 = 33.66 GALLONS
Note: This is if it is filled to the brim with water. The final volume will be LESSER since we will take into account the water being displaced by the things inside your tank (gravel and other decors) and the inch or two you leave on top. The final volume would probably be 30 GALLONS
Note: All dimensions must be in inches to use this formula, so convert all other units beforehand. The number 231 is a constant.